The Muggle Murder
by SJAandDWfan
Summary: A muggle-born student is stabbed and killed at Hogwarts, and as per her parents' wishes, NCIS investigate. But that meant letting them into the secret. Set after HP OotP and NCIS S7. Possibly Tony/Ziva Ron/Hermione and Harry/Ginny. My first crossover fic!
1. The Call

**M'kay, I'm not entirely sure how this is going to go as I've written a Harry Potter fic and an NCIS fic, but never together. So I'm going to play the first few chapters by ear, and if you like, I'll write more. If you don't, I won't.**

**DISCLAIMER: I don't own either NCIS or Harry Potter, just this plot. If I did, I would be able to look into the Mirror of Erised and see myself as I am.**

**There will probably be Tony/Ziva and maybe Ron/Hermione and Harry/Ginny.**

**This story takes place after HP Order of the Phoenix and after NCIS Season 7. AU after those.**

"Has anyone seen Lavender Brown?"

This question was echoed through the halls of Hogwarts for hours before an answer was found. Minerva McGonagall straightened up sadly after crouching over her body; she'd tried everything she could, but by then the girl was gone. A dark pool of blood spread out from her, pouring from a deep wound in her front. McGonagall couldn't understand it. This wasn't the work of any curse. Lavender had been murdered in a crude, _muggle _way.

After sending her patronus to the other professors, she examined the location. A long abandoned classroom just off a corridor on the fourth floor. The classroom hadn't been occupied in years. Tables and chairs were heaped against the wall, and Lavender was sprawled in the middle of the floor, spread-eagled. _Who would do such a thing? _McGonagall thought to herself, as she brushed away the tears that started to form.

"Tony, if you flick one more paper ball at me, I will kill you with my bare hands!" Ziva hissed at her partner, after yet another missile hit her on the head.

McGee, not looking up from his keyboard, said, "She's probably not kidding, Tony."

Tony laughed. "Oh, I know she's not kidding, McSmarty Pants, I'm just trying to get her attention."

McGee rolled his eyes. "Of course you were."

Ziva calmed herself mentally. Although Tony frequently got on her nerves, she had to admit, she liked him. She hated that she loved him, but it had been that way for a few years now, so she was getting pretty good at hiding her feelings, not letting it interfere with her job. Speaking of which…

There hadn't been much to do lately. No murders in a week; a new record. So they did paperwork. Lots and lots of paperwork, and it was driving them all insane. She only wished they could catch a case before she started a killing spree.

"But are you sure, Professor Dumbledore?" McGonagall asked urgently, "They are _muggles, _after all."

Dumbledore bowed his head. "Yes, I am sure. Miss Brown's parents wanted them specifically to investigate. If you recall, Minerva, her father did work there once, he trusts these people."

McGonagall unwillingly agreed with Dumbledore. She just didn't see why they had to let more muggles know about them. But the wishes of Lavender's parents had to be respected.

"Now if you'll excuse me, I have to make a trip to the Ministry." He said, standing up.

Gibbs strolled into the bullpen, fresh coffee in hand. "Grab your gear, we've got a weird one." Was all he said.

The team sighed in relief, and sized their rucksacks. But Gibbs walked straight past them, to the elevators, calling over his shoulder, "Go home and pack. We fly out in four hours."

"Where are we going?" Tony called after his retreating back.

"Scotland." Came the snatched reply. "Need the rest of the team for this one."

Tony turned to the other two.

"_Scotland?" _

After a long flight, they finally touched down in Scotland. Exactly where they were, they didn't know, but the first thing they registered was the temperature. It was _freezing._

"At least I remembered thermal underwear this time!" Tony told the rest of the team brightly. Ziva snorted with laughter, which Tony caught.

"I wouldn't laugh, if I were you, _Zee-vah,_"he breathed in her ear, causing chills to run down her spine, which had nothing to do with the cold, "they're your thermal underwear."

He grinned at her expression. "Told you they'd stretch."

The only team member who seemed right at home was Ducky. Being from Scotland himself, he wasted no time in telling the rest of the team all about his childhood playing in the snow, and visiting his relatives in Newcastle, just south of the Scottish border.

They were greeted outside the terminal by a man in a pinstriped suit, his scraggy hair framing his thin, scarred face. He looked almost like an old lion.

"Rufus Scrimegeor." He introduced himself, holding out his hand for Gibbs to shake. "I'm the Minister of Magic."

**Like? Hate? Sorry it was so short, if you want more chapters, they'll be longer, but I'd like to know if you want me to continue.**

**By the way, the whole 'thermal underwear' exchange was a call-back to the NCIS episode "Faith". Just thought it was a great opportunity to throw it in.**


	2. The Arrival

**Ok, I think I'll carry the story on after all. Thanks for all the alerts and favourites, and a special thank you to SaikohBellaL and serenity8118 for reviewing!**

**I know it's quite soon after the first chapter, but I'm in a write-y mood!**

**Once again, I don't own Harry Potter or NCIS!**

"Magic, wow! Can you believe it? I can't believe it!"

Abby had been continuing in this vein for several minutes now, and even Gibbs, who was like a father to Abby and let her get away with anything, was starting to get annoyed. Rufus Scrimegeor had explained to them all about magic, and wizards, and a school called Hogwarts where the murder had taken place. It was taking a while for this all to sink in.

Strangely enough, Ziva seemed the most open to the idea. When questioned by McGee on her open-mindedness, she replied that in Mossad, she had been taught to accept that there were things science and rational thinking just couldn't explain, like she had said a couple of years ago on the _Chimera. _McGee himself was now in a happy daze; after all, he was an Elf Lord online, and magic is a completely different thing when it's happening for real.

Ducky was for once at a loss for words, and Palmer was just muttering a few things over and over again, occasionally shaking his head, almost like a dog trying to rid its ears of water.Gibbs just sat there, flatly refusing to believe in magic until he saw it with his own eyes, and Tony wasn't sure what to feel; he badly wanted to believe it was all for real, but he couldn't help but retain some scepticism.

Abby, on the other hand, was still chattering excitedly, tugging on McGee's sleeve like a small child about to go to the Theme Park for the first time, so excited, and yet slightly nervous. Ziva smiled to herself at the Forensic Scientist's enthusiasm, and at McGee's almost doting look to her as he attempted to ease her word flow.

Scrimegeor had them driven to the village, Hogsmeade, by a wizard driver in a car. This car didn't look like much on the outside, but it seemed huge on the inside. McGee squeaked something about the TARDIS, which went straight over Ziva's head, but Abby agreed completely. Inside, the car had more than enough room for all of them, and Scrimegeor waved them off from outside the airport. Tony twisted around in his seat to watch him as they drove off, but the man had already disappeared.

It wasn't that long a drive, and by the time they'd reached Hogsmeade, everyone's eyes were wide. First of all, what village was called _Hogsmeade? _Although, what school was called Hogwarts? They all scrambled out of the car, and grabbed their suitcases and equipment from the boot of the car, also deceivingly small-looking on the outside. But then they stopped dead in their tracks.

In front of them stood two carriages, for want of a better word, pulled by what looked to be skeletal black horses with wings. The driver saw them staring and chuckled.

"Thestrals," he explained, although no one knew what he meant, "They can only be seen by people who've witnessed death."

"Seen a lot of that around, though," Gibbs reasoned, "being cops and all."

The driver nodded and opened the door to the first carriage.

"Who's feeling brave?"

Ziva stepped forward unhesitatingly, smiling to herself again as she climbed in. Gibbs and Tony followed her, and the driver got in, too. Ducky, Palmer, Abby and McGee clambered into the other carriage and the Thestrals started off up a gravely drive which seemed to stretch on for at least a few miles.

The driver chatted to them all the way up the drive, welcoming them to the 'wizarding world', as he called it. Finally, Gibbs interrupted him.

"Why are we here?" he asked bluntly.

The driver shrugged. "You'd have to ask Dumbledore, I don't know."

"Who is Dumbledore?" Ziva asked.

The driver laughed. "Oh, he's only the greatest headmaster of Hogwarts there's ever been! Just wait 'till you meet him."

After about fifteen minutes, they arrived. Jumping down from the carriage first, Ziva stopped abruptly when she reached the ground. Standing, bathed in a golden glow, was the most magnificent castle she'd ever seen. She turned around to tell the others this, but a body slammed into her, sending them both to the floor. Tony had apparently not been watching where he was going.

"Hi," he said innocently, nose-to-nose with her, "thanks for breaking my fall."

"Tony!" Ziva gasped. "You're crushing me!"

He grinned. "Oh, yeah. Sorry about that."

"Can you get off me, now?"

Tony's smile widened, "What's the magic word?" he asked sweetly.

"Hey!"

Tony leapt off Ziva as if electrocuted, looking for the all-too-familiar owner of the voice. It was Gibbs, and he was scowling at them. "You two done playing grab-ass?"

"Yes, boss." Tony said, as Ziva stood up and dusted herself off, slightly pink in the cheeks. Gibbs just rolled his eyes at them, as he seemed to be doing a lot lately. Meanwhile, the other carriage had pulled up at the gates to the castle.

Abby's eyes went wide at the sight of the castle, like a kid on Christmas morning. The driver gestured to it proudly.

"This here…is Hogwarts School of Witchcraft and Wizardry!"

"Cool…" McGee breathed.

Ziva narrowed her eyes, squinting at something. "What is that?" she said, pointing to a light bobbing up and down in the dusk, getting closer to them.

The driver followed her line of sight." Oh, that'll be Filch, the caretaker. Temper if ever there was one, mind. Be careful of him."

And sure enough, a small, balding man with bulging eyes came wheezing up to the gates, holding a large, luminous lantern, a skeletal-grey tabby cat winding herself around his ankles. When he caught sight of them, he grunted something that sounded like 'muggles'. The team turned to the driver in confusion.

"A muggle is a word for someone who isn't magical, someone like yourselves." He explained kindly.

With that cleared up, Filch dismissed the driver – who waved a cheery goodbye to the team – and escorted them up to the heavy, oak front doors of the castle. His cat mewed at them all the way up, obviously not liking their presence. Filch rapped three times on the door, and it swung open to reveal a tight-lipped, grey-haired witch in long black robes and a tall pointed hat. She smiled thinly at the team.

"Hello," she said, with a Scottish accent, "I'm Minerva McGonagall. I will be escorting you from here."

She thanked Filch, who just grunted again, and led them into the castle.

Gibbs had insisted they get straight down to business. After all, they were here to work.

"Her name is Lavender Brown." McGonagall had said to them, "She's sixteen years old, in her sixth year here. To stop the decomposing, we've preserved her as she was when we found her."

They found the dead girl sprawled in the middle of an abandoned classroom, encircled in a large pool of shockingly scarlet blood, eyes wide and mouth gaping. Ducky knelt down beside her.

"Cause of death appears to be a stab wound, delivered just below the ribcage." He observed, inserting the liver temp reader, before remembering she'd been preserved. "Do we have a time of death?" he asked McGonagall.

She nodded. "Two days ago, around ten in the evening."

"That's nearly forty-eight hours ago." Ziva observed.

Gibbs turned to face McGonagall. "Why are _we _investigating this?"

"Both her parents are in the muggle Navy." She explained, "Her father even worked as a Field Agent, as I believe you call them, for a few years. They wished for NCIS – specifically your branch – to investigate."

Tony looked up from where he was photographing the body, as if struck by a sudden thought.

"Hang on, how and Palmer going to perform the autopsy here?"

"Yeah, and how am I going to do my stuff with the forensic evidence?" Abby agreed. McGonagall waved an indifferent hand.

"It's fine, we've set everything up as you would expect it in the dungeons. Now, if you're finished with the body here, you may eat dinner with the students and other teachers whilst I escort the body down to, ah, _Autopsy_."

So the team stood in the corridor outside the classroom, none of them quite sure where to go or how to find dinner. Just as they agreed to ask McGonagall again, three students walked by, talking amongst themselves. The girl, however, spotted the NCIS team, and smiled warmly at them.

"Hello, you must be the muggle investigators." She said. When the team nodded mutely, she elaborated, "Dumbledore told us you'd be arriving tonight. I'm Hermione Granger, by the way."

Hermione held out her hand for them all to shake. She looked about sixteen, as did the two boys she was with, and she had bushy brown hair and chocolate-coloured eyes. She was shorter than her companions.

"This is Ronald Weasley…" she gestured to a tall boy with flaming red hair, who muttered, 'Ron', and shook their hands, too.

"And this is Harry Potter." Hermione introduced the other boy, who had messy, jet-black hair and green eyes. Round glasses were perched on his nose, and he carried a thin, lightning-shaped scar on his forehead.

The team introduced themselves, and Hermione, who seemed to be doing most of the talking, offered to show them where the Great Hall was. She led them through a maze of halls, until they reached more, large double doors that opened into the most bizarre room any of them had ever seen.

There were four long tables dotted with hundreds of chatting students, along with a fifth on a raised platform at the far end of the room, and the Great Hall appeared to be missing its ceiling. Noticing their gaze, Harry said, "Oh, the ceiling's still there, it's just enchanted to look like the sky above it."

He said this as if it were perfectly normal.

Meanwhile, a hush had fallen in the hall upon the team's arrival. Ignoring them, Hermione, Harry and Ron led them up to the teacher's table at the back of the hall.

"NCIS are here." Harry said to a tall, thin wizard. He was old-looking, and he had silver hair and a white beard long enough to tuck into his belt. His eyes twinkled behind spectacles, which sat on his crooked nose. He beamed at them all.

"Albus Dumbledore, headmaster of Hogwarts." He introduced himself, shaking hands all around, then raising his hands to get the students' attention.

"As I'm sure you all know by now, Lavender Brown, one of our own, was murdered in a horrible, muggle way. Due to her parents' wishes, NCIS are investigating her death. They will be talking to many of you, and will be staying here until Miss Brown's murder is solved. Therefore, I ask that you show them the greatest hospitality during this troubled time."

Dumbledore looked at the team. "Let's see if I've got this right." He mused, "OK, this here is Special Agent Leroy Jethro Gibbs; I believe he's the team leader." Polite applause finished his comment, and Gibbs nodded curtly. "Making up his field team are Special Agent Timothy McGee, Special Agent Anthony DiNozzo, and Probationary Agent Ziva David." He said.

"Um, _Dah-veed._" Ziva corrected politely.

"Ah, yes, my apologies. The Medical Examiner Dr Donald Mallard, and his assistant Jimmy Palmer and last – but not least- Forensic Scientist Abigail Scuito."

Dumbledore turned to them.

"Sit where you please." He said, "I hope you enjoy your stay, and you may want to start taking statements tomorrow, when we are all fresh."

**Like? Hate? Either way, reviews are very much appreciated!**


	3. The First Night

**Sorry it's been a few days, I was staying with my grandparents and they aren't big on technology, but thanks to everyone who's reviewed or put me on story alert!**

**OK, I'm pretty sure I know vaguely where I'm going with this, but I'm open to suggestions about suspects or stuff.**

The food was amazing.

Piles of roast and boiled potatoes, beef and lamb and whole chickens, tureens of steaming vegetables, sausages and so much more were heaped on plates. The NCIS team sat at the Gryffindor table with Hermione, Ron and Harry, who, between mouthfuls of food, were explaining about Hogwarts, its houses, and Quidditch, something which Ron and Harry took particular interest in.

"Anyway, I've already talked to Dumbledore. It's been arranged; you'll all stay in Gryffindor tower, with the sixth years. There's extra beds, the guys might be a bit cramped but I'm sure it'll be fine…" Hermione just couldn't seem to stop talking. Ron and Harry's eyes met and Ron suppressed a snort. According to Hermione, Ziva and Abby were to stay with her and the other sixth year Gryffindor girls, and Tony, McGee, Gibbs, Ducky and Palmer would go with Ron and Harry, joining the boys during their stay. Like she'd said, Hermione had it all arranged.

"Hermione," Ron finally interrupted her, "your food's gone cold."

After pudding, the team could barely keep their eyes open. Harry noticed.

"Yeah, the food does tend to do that to you. You'll get used to it."

Together, they departed the Great Hall for Gryffindor Tower. The team trudged after the teens through an endless maze of halls and stairs. The stairs woke them up slightly. Tony got a shock when the step he had just put his foot on disappeared from underneath him, and McGee nearly jumped out of his skin when one of the staircases started to move. Harry, Ron and Hermione seemed to find this perfectly normal, however.

Finally, they drew to a halt in front of a huge portrait of a woman. Another surprise was in store when she moved, settling in her seat, and asked, "Password?"

Hermione swallowed before answering, "The Fallen One."

The portrait nodded grimly, and swung forward, revealing a hole in the wall that the students climbed through. The team glanced quickly at each other before following suit. It seemed the dead girl had belonged to this house.

Once in the common room, Ducky, Palmer and Abby excused themselves to get to work on the body and evidence, respectively. Harry offered to escort them down to the dungeons, which they appeared grateful for. This left Gibbs, Tony, Ziva and McGee with Ron, Hermione, and a room full of curious wizards. A round-faced sixteen year old boy eyed their guns nervously.

"Oh, calm down, Neville, they're not going to shoot you." Hermione laughed.

The tension in the room seemed to ease a bit. Ron turned to McGee, Gibbs and Tony.

"C'mon, I'll show you where you're going to be staying." He lumbered up a spiral staircase, the three trailing behind him.

Hermione watched him go with an unreadable expression, but if Ziva had to guess, it could be described as a furtive look. Tony glanced back at Ziva and grimaced comically, which made her smile. Hermione finally looked at Ziva.

"Do you want me to show you where you and Abby'll sleep?"

"Sure."

The dorm room was nice enough, Ziva decided, but she could really do with having Abby there. She wasn't afraid or intimidated, but it would be nice to have someone there she knew. As soon as she and Hermione entered, three girls hurried over to speak to them, each asking did she know who had killed their friend. Ziva noticed tears still streaked one's face.

"Hold it!"

The voice came from behind them. A girl, slightly younger than the owners of the dorm, with a long mane of dark red hair, stepped inside.

"Ginny," Hermione said in relief.

The girl, Ginny, smiled reassuringly at Hermione, then addressed Ziva.

"Hey, I'm Ginny Weasley, you may have already met my idiot brother, Ron." She introduced herself cheerfully, though Ziva could sense a lot of her tone was forced. It seemed Lavender's death had really messed up their life.

She suddenly realised everyone was looking expectantly at her.

"My name is Ziva David," she said, "I'm a Probationary Agent at NCIS, former Mossad Liaison Officer."

Only Hermione seemed to understand this, however. She gasped.

"You were with Mossad?"

Ziva nodded.

"How ever did you survive?" Hermione asked, and the girls looked at Ziva with new-found respect.

"It's what I'm trained to do." She sighed, "Most of my family were not so lucky."

The girls led Ziva over to a spare bed with sympathetic expressions, and Ziva knew she was cornered, expected to elaborate. If she was to gain their trust, she'd have to tell them.

"My mother and sister died in a bombing when I was about eighteen. I wasn't there, I was serving in the Israeli Army at the time." She paused, as if uncertain whether to continue, but she did, "My half-brother, Ari, I was his Control Officer in Mossad, but he went rogue, went bad. He was shot."

Ziva neglected to mention that she was the one who shot him. "And my father, he's still alive, but – "

The girls noticed her voice had suddenly hardened.

"– He does not care for me." Ziva stopped talking, and it was clear she had finished. She was sitting cross-legged on the bed, but she stood up and removed her NCIS cap. "It's late, you girls should probably sleep."

"Aren't you going to?" Hermione asked, concerned.

"No. Gibbs told me to provide security for you, just in case."

Ziva took her gun out if its holster and checked it over, making sure there was nothing wrong. Once she was sure, she re-holstered it, and did the same for the smaller gun strapped to her ankle. Finally, she took a retractable knife from the pocket of her combats, and checked that, too. When she returned it to her pocket, she found their eyes trained on her, mouths open. She shrugged.

"Rule number nine: Never go anywhere without a knife." She recited. "Don't worry, you'll be perfectly safe."

Meanwhile, in the boys' dorms, Tony was cracking jokes with Ron and a sandy-haired boy who'd introduced himself as Seamus Finnigan. McGee was chatting animatedly with Neville, who looked calmer about their presence now he knew they were friendly. Gibbs and Harry were talking a short distance away from the others.

"Lavender was muggle-born." Harry was saying. Seeing Gibbs' confused look, he elaborated, "Her parents were like you, non-magic. If it were up to me, I'd investigate Slytherin. They're famous for their hatred of muggle-borns."

Gibbs nodded. "We'll be sure to talk to them in the morning. We're going to have to interview all of you, by the way."

"Not a problem," Harry said, "but we should probably get some sleep now."

"Sure," Gibbs said, "but one of us'll keep watch, just in case the killer tries anything."

**Again, sorry about the wait.**

**I've had several story alerts, but not so many reviews, so I'd be grateful if you could leave one, or if you have any suggestions. I know I haven't shown much Tiva, Harry/Ginny or Ron/Hermione, but that'll pick up in the next chapter. I also might add in some McAbby. These first few chapters were setting up the story really.**


End file.
